Vulnerability in Openclaw
CVE-2026-42421
OpenClaw before 2026.4.8 contains a session management vulnerability where existing WebSocket sessions survive shared gateway token rotation. Attackers can maintain unauthorized access to WebSocket connections after token rotation by exploiting the failure to disconnect existing shared-token sessions.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.003 (22.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 23rd percentile — 22.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001
Affected products
- Openclaw — versions 0, 2026.4.8
Weakness classification (CWE)
References
- github.com/openclaw/openclaw/security/advisories/GHSA-5h3f-885m-v22w (vendor-advisory, Vendor Advisory)
- github.com/openclaw/openclaw/commit/d7c3210cd6f5fdfdc1beff4c9541673e814354d5 (Patch, patch)
- www.vulncheck.com/advisories/openclaw-websocket-session-persistence-via-shared-… (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-42421?
- CVE-2026-42421 is a medium-severity vulnerability in Openclaw, classified under Insufficient Session Expiration. CVSS score: 5.4/10. Published 2026-04-28.
- How severe is CVE-2026-42421?
- Medium severity. CVSS v3 base score is 5.4 out of 10.